Will aminopyralid plan save us from ‘bad manure’? 

What do growers make of the news that the herbicide agent aminopyralid, which was taken off the market by its makers in June 2008, has been recommended for reinstatement to the market?

Sales and use of herbicides containing the hormone-based weedkiller were suspended by manufacturer Dow AgroSciences last summer, after growers began to suspect that animal manure containing the product had been damaging their crops.

It emerged that aminopyralid – used to kill broad-leafed plants growing amongst grass – was ’sticking’ to plant material used for animals’ bedding and feed, and ending up in manure. There it remained active for long enough to affect plants grown in the soil onto which that manure was applied.

However, the latest meeting of the Advisory Committee on Pesticides recommended that the product be reinstated – subject to a stewardship scheme designed to ensure the herbicide is used correctly.

The stewardship rules include clearer and more rigorous instructions, a ban on using grass sprayed with the herbicide for hay or silage, and a ban on manure that might contain residues being passed on to growers.

Unconvinced

The main points of the stewardship are summarised on the website of Green Lane Allotments, where growers noticed problems with a variety of produce last year.

Susan Garrett, chair of the group, has been carefully following the unfolding events, and documenting reports from allotment holders and gardeners who appear to have been affected.

She believes that despite the makers and the conditions of the stewardship taking all possible precautions, it will still be difficult to guard against human carelessness in using herbicides.

"There’s nothing else they could have done to inform people about how to use it, but it comes down to people not reading the instructions on the label," she said.

"Increasing the power of the instructions isn’t going to stop that."

While the problems that arose at Green Lane last year have passed, Susan worries that people may cut corners again if ministers decide to reapprove the product for sale."The stewardship says that any manure created from plants which have been treated with aminopyralid should stay on the same farm," she added.

"But it’s whether that’s done or not – that’s the crux of the matter."

"So how do they get rid of it? Farmers and stable owners rely on off-loading manure into horticulture."

Even ‘organic’ wasn’t safe

Last year’s scandal highlighted the fact that the Soil Association approves manure from non-organic sources as suitable for use by organic growers. It does this because agricultural chemicals tend to have broken down before they reach the field, allotment or garden – but also because there simply isn’t enough manure produced by organic farms.

Understandably, the Soil Association has expressed alarm at the prospect of aminopyralid being reinstated, and has written to Defra minister Hillary Benn demanding that its use remains suspended.

And although the Pesticides Safety Directorate found last year that eating food grown with manure containing aminopyralid had no implications for human health, the incident has fuelled disquiet about what else might be passing through the food chain unnoticed and untested – even in the organic sector.

For now, there is an e-petition asking the Prime Minister not to allow aminopyralid’s re-instatement that has thus far attracted over 1,500 signatories.

Next move: the Government’s.

TOMATO IMAGE by Flickr user Oquendo
MANURE SIGN IMAGE by Flickr user batsignal